LARGER VIEW of a heating boiler circulator pump setGuide to Circulator Pump Relays & Other Controls for Heating System Circulator Pumps
Circulator Relays Explained

  • CIRCULATOR PUMP RELAYS & OTHER CONTROLS - CONTENTS: Circulator pump relays & other controls and switches. Circulator Pumps: Hot Water Heating System Circulator Troubleshooting & Repair Guide. Circulator pump relay switches & controls on heating systems.:
  • POST a QUESTION or READ FAQs about heating circulator pump diagnosis & repair: what controls run the circulators? How should those controls be adjusted?

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Heating system circulator pump troubleshooting: here we list & describe other heating system controls that manage or impact heating boiler circulator pump operation.

Troubleshooting & Repair Guide for hot water heating circulator pumps. How to tell if a heating circulator pump is working. Why do some heating zones work and others not, why does heat come out of zones where thermostats are not calling for heat? How to fix an air-bound heating system and blocked circulator pump. Where should a circulator pump be installed on a heating boiler? On the inlet or on the outlet side of the boiler?

This article series discusses Circulator Pumps: how to find, inspect, diagnose, and repair problems with Hot Water Heating System Circulator Pumps or circulator pump relay switches and controls. This article series answers most questions about Heating System Boiler Controls on central heating systems to aid in troubleshooting, inspection, diagnosis, and repairs.

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Other heating system controls related to hot water circulator pumps - three alternative ways to control hot water heat circulation

Honeywell R8182D Aquastat (C) Daniel Friedman Circulator Relay (C) Daniel Friedman\ Zone valve (C) Daniel Friedman\

Variable Speed Hot Water Heating Circulator Pumps, Motors & Controls

B&G UpStart circulator with variable speed motor (C) Daniel Friedman

Shown above is a Bell & Gossett UpStart hot water heating zone circulator pump produced - a B&G product no longer distributed.

Controls for this circulator pump included a knob on the circulator that adjusted a variable-speed circulator motor to select one of speeds operated by a four-speed motor - the circulator output rate could be set by the consumer or heating service technician.

By changing the circulator motor speed we can slow or speed the flow rate of hot water through the zone managed by the circulator. This provides another way to balance heat flow among multiple zones (and circulators) in a building.

This circulator, the Bell & Gossett SLC-25 Upstart Circulator was sold during the 1980's and is not currently available. But B&G offered similar replacements (such as the NRF-22) and currently variable speed circulators are available from Taco and Grundfos.

At CIRCULATORS VARIABLE SPEED we describe these products and their controls.

If the heating boiler itself if does not turn on in a response to a call for heat see NO HEAT - BOILER.

Hot Water (Hydronic) Heating Boiler Circulator Articles


Continue reading at CIRCULATOR PUMP WON'T START or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

If you are not getting any heat at all out of a cold baseboard or radiator, see COLD HOT WATER BASEBOARD / RADIATOR

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CIRCULATOR PUMP RELAYS & OTHER CONTROLS at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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